Oliver AG-6 Service Manual. Written in the language of a mechanic, this Service Manual for Oliver provides detailed information on how to take your Cletrac Crawler apart, fix it, and put it back together. You will need this manual if your Oliver is broken. Also known as the Repair, Shop, Technical, IT, Overhaul manual. This is a 76 page factory written reproduction service manual and would have been given to the dealer service shops back when your equipment was new.